New (old) house, broken heating system

[jimsbrokenhouse]

Morning all, hoping someone can help me.

After years of renting we've just bought a house (1950s ex council semi) and I'm trying to wrap my head around the
heating system - I've only ever seen combis before, except my parents' old fully pumped conventional system - but
just can't work out what's going on.

The boiler is an old Halstead Best 40, the cylinder is the original from the 70s (heavily patched up with some
white stuff, must have leaked before) and there are the usual two tanks in the loft. The boiler has a 28mm out and
a 22mm (I think) in, connected to the central heating ring (according to the manual). The hot water in/out isn't
connected. The radiators all work fine (ancient microbore, I think 8mm, no thermo valves) but the cylinder doesn't
heat up - the input pipe doesn't even get warm. Currently using the immersion for HW, which is also ancient but
still works. There's one pump, just next to the boiler, and no motorised valves or anything else. Not even a room
thermostat (well, it's not connected). The controller is relatively new.

I tried disconnecting the pump and running it up to see if the tank heated up but unsurprisingly the boiler just
cut out after a minute of heating water that wasn't being taken away. There are two big red valves, one on the
cylinder output and one near the boiler, both are open.

We knew when we bought the place that the hot water didn't work and were hoping it would be a simple fix, but have
the money put aside to sort it if not. We've had a few blokes over but they've all been pushing to just tear the
whole thing out, radiators and all, and fit a combi. We can just about afford this, but don't want to tear the
whole house up and have to replaster/decorate the whole thing and live in a warzone for weeks.

So, questions are:
Do I have a pumped CH, gravity HW system?
Why is the cylinder not heating up when the CH is turned on?
Can it be fixed by draining down, power flushing and replacing the cylinder? If so, roughly how much will it cost?
Can we fit a combi and keep the microbore if it's flushed out?
Should we do that rather than keeping the boiler and replacing the cylinder/fixing the HW problem?
Or should we just suck it up and tear out the whole thing?

Thanks in advance - I know it's a huge post and probably not enough info to go on. I've gotten as far as I can
with my own research and getting people over but really not sure which option to explore!

 

[Plumber90]

By the looks of things you have pumped heating and gravity hot water if there are no motorised valves

If you replaced the cylinder and changed it all to fully pumped the chances are it could fix your problems.

Power flushing microbore is a bit hit and miss, some people say its pointless due to not being able to get a high enough flow of water down the pipes due to their size.

What is your location as that plays a big part on the price of what you will pay.

 

[jackthom]

It does sound like a gravity feed for the hot water and there may be something simple like an airlock stopping it working. Can you supply some pictures of the system?

I agree going fully pumped by installing a new cylinder and a 3 port valve would make for a much better system.

 

[jimsbrokenhouse]

Thanks both - looks like the minimum work is going to be flushing the rads, replacing the cylinder and adding valves and a second pump then. We're on the outskirts of Nottingham, being quoted ~£1500 to refresh what we've got and ~£2800 to tear it all out and start again with a combi. The layout of the house means it's going to be floorboards up all over the place either way. Guess we'll mull it over until spring and hope the immersion doesn't pack in before then!

Cheers again